Variable resistance slide control

ABSTRACT

A variable resistance slide control employs a housing having a front wall and a side wall integral therewith. A dielectric base having a resistance element and a collector element mounted thereon is secured to the housing in spaced parallel relationship to the side wall. A contactor engaging the resistance and collector element is constrained to move with a slider projecting outwardly of the housing through an elongated slot defined by the front wall and the base. The slider comprises a U-shaped section bearing against and interfitting with the front wall, a contactor frame provided with a pair of runners engaging the side wall, and a tolerance compensator limiting lateral movement of the slider. A pair of terminals secure the resistance element to the base and a bowed portion integral with each of the terminals electrically engages the resistance element at the innermost portion of the terminals.

United States Patent 1191 Rozema et al.

[ June 3, 1975 VARIABLE RESISTANCE SLIDE CONTROL [75] Inventors: ArthurL. Rozema; John D. Saik;

Mervin B. Arisman, all of Elkhart,

Ind.

[73] Assignee: CTS Corporation, Elkhart, Ind.

[22] Filed: July 16, 1973 21 Appl. No.: 379,719

52 11.8. c1 338/183; 338/322 51 Im. 01 ..H01c 9/02 [58] Field of Search338/183, 176, 174, 162, 338/322, 313, 312, 332; 339/95 R, 17 R [56]References Cited UNITED STATES PATENTS 3,412,361 11/1968 Lovejoy et al.338/183 X 3,550,059 12/1970 Barden et al. 338/183 X 3,588,779 6/1971Goerg 338/183 3,735,327 I 5/1973 Rozema et a1. 338/176 X PrimaryExaminer--J. V. Truhe Assistant Examiner-David A. Tone Attorney, Agent,or FirmJohn J. Gaydos [5 7 ABSTRACT A variable resistance slide controlemploys a housing having a front wall and a side wall integraltherewith. A dielectric base having a resistance element and a collectorelement mounted thereon is secured to the housing in spaced parallelrelationship to the side wall. A contactor engaging the resistance andcollector element is constrained to move with a slider projectingoutwardly of the housing through an elongated slot defined by the frontwall and the base. The slider comprises a U-shaped section bearingagainst and interfitting with the front wall, a contactor frame providedwith a pair of runners engaging the side wall, and a tolerancecompensator limiting lateral movement of the slider. A pair of terminalssecure the resistan'ce element to the base and a bowed portion integralwith each of the terminals electrically engages the resistance elementat the innermost portion of the terminals.

1-8 Claims, 7 Drawing Figures VARIABLE RESISTANCE SLIDE CONTROL Thepresent invention relates to a variable resistance control and moreparticularly to a variable resistance slide control having a slidermovable rectilinearly in the housing.

Variable resistance slide controls provided with a slider carrying acontactor wipingly engaging a resistance element and a collector elementare well known in the art. In certain prior art slide controls, thehousing is generally made from two substantially identical molded halfsections joined to leave a slot in the front wall of the housing, and aslider having a gripping portion extending through the slot wipinglyengages the resistance and collector elements mounted in the housing.The slider bears on the front wall of the housing of the joined halfsections defining the slot and, during movement rectilinearly along theslot, the slider frequently jumps, skips or rocks. This eratic motion ofthe slider is caused in part by misalignment of the two spaced surfacesof the front wall formed upon joining together the two half sections ofthe housing, thus causing the slider to bear unevenly on the surfacessupporting the slider. Eratic motion of the slider is also partiallycaused by the large tolerances required in the manufacture and assemblyof the half sections of the housing and slider. It would therefore bedesirable to provide a variable resistance slide control having asmoother and more uniform slider movement.

Prior art slide controls are provided with an elongated longitudinalslot in the front wall of a housing and the gripping portion of a sliderprojects through such slot. In many applications, such slide control ismounted with the slot in the front wall visible to the operator. This isobjectionable not only because the inside of the control is visible butalso because it encourages insertion of foreign objects into the slot incontact with the resistance and collector elements presenting potentialelectrical shock hazards. Various means have been suggested for closingthe slot in order to prevent exposure. Generally such closing meansincreases the cost and complexity of manufacture and assembly of thecontrol, such as the use of a shield as shown in US. Pat. No. 3,676,826or the use of a special slider drive and additional carrier blockassembly as shown in US. Pat. No. 3,588,779. It would, therefore, bedesirable to provide a variable resistance slide control that can beassembled and manufactured in a simple and facile manner and yet isprotected against the ingress of foreign objects into the housing inpossible contact with the resistance and conductive elements from thefront or operators side of the slide control as well as providing acontrol that eliminates from the front view visible exposure of theinside of the control.

Various types of terminal structures have been devised for variableresistance controls for securing electrical terminals to the resistanceelement and for securing the terminals and the resistance element to abase as well as providing good electrical Contact between the terminalsand the end of the resistance path of the resistance element. It isdesirable that the hop-off resis tance, defined as the residualresistance between the end of the resistance path on the resistanceelement and that portion of the resistance element spaced apart from theend of the path that makes positive electrical contact with theterminal, be at a minimum. Prior art termination means, such asdisclosed in US. Pat. No. 2,632,832, secure the resistance element to abase with a U-shaped terminal embracing the resistance element tabsextending radially from the resistance element. The legs of the U-shapedtenninal passing through holes in the base are staked to the base tosecure the resistance element and the terminal to the base, resulting ina portion of the terminal making positive electrical contact with theresistance element. The difficulty with this prior art construction isthe inability to maintain a flat surface to surface engagement betweenthe resistance tab and the U-shaped terminal to assure a positiveelectrical connection unless the staking pressure is held closely withinrather critical limits. Other prior art US. Pat. Nos. 2,736,783 and2,958,839 also show termination structures having a protuberanceengaging the resistance end tab to assure a positive electricalconnection. Although such terminal constructions with the protuberancescentered on the end tabs are satisfactory for certain controlapplications, other applications require an electrical connection asclose as possible, preferably at the innermost end of the resistancepath on the resistance element. Such connection between the terminal andthe resistance path greatly minimizes the hop-off resistance. On theother hand if the terminal engages the resistance path, then thecontactor on the slider will abut against the terminal before thecontact engages the end of the resistance path. In preferred designpractice, the contactor should not abut against the terminal whichresults in a finite amount of resistance left in the circuit. Therefore,it would be desirable to provide a termination means having a positiveelectrical connection as close to the end of the resistance path aspossible, a minimum residual resistance between the end of theresistance path and its end terminal, and means securely attaching suchterminal and the resistance element to the base.

Accordingly, it is an object of the present invention, to provide animproved variable resistance slide control. Another object of thepresent invention is to provide a variable resistance slide controlcapable of being finely adjusted without having the slider jump or skip.A further object of the present invention is to provide a variableresistance slide control that can be assembled and manufactured in asimple and facile manner. Still another object of the present inventionis to provide a control housing with a slot in the corner of the housingdefined by a front wall and a side wall having an indented base therebypreventing the ingress of harmful objects into the resistance andcollector element from the front side of the housing. Another object ofthe present invention is to provide a variable resistance slide controlwith a slider having a U-shaped section slidably engaging the inner andouter surfaces of the front wall of the housing. Yet another object ofthe present invention is to provide a resistance element terminationthat minimizes the residual resistance between the resistance path andthe end terminal and securely attaches the end terminal and theresistance element to the base. Still another object of the presentinvention is to provide a terminal with a bowed portion having an edgemaking electrical contact with the resistance element. Further objectsand advantages of the present invention will become apparent as thefollowing description proceeds, and the features of noveltycharacterizing the invention will be pointed out with particularity inthe claims annexed to and forming a part of this specification.

Briefly, the present invention is concerned with a variable resistanceslide control employing a contactor wipably engaging a resistanceelement and a collector element supported by a dielectric base securedto a metal L-shaped housing. The legs of the L-shaped housing areintegral and define the front wall and the side wall and, in a preferredembodiment, a rear wall and a pair of end walls are also formedintegrally with the side wall. Integral mounting brackets extendingforwardly, rearwardly or sidewardly from the two end walls are employedfor fastening the control to a mounting panel. A control operating meansor slider comprising a U-shaped section having an integral resilientbearing engages the inner and outer surfaces of the front wall of thehousing. The contactor is constrained to move with the slider. Thedielectric base secured to the housing in spaced parallel relationshipto the side wall is provided with an elongated indentation defining aslot adjacent to the front wall through which a portion of the sliderprojects externally of the housing for operating the slider. A pair ofterminals secure the resistance element to the base. Each of theterminals has a bowed portion making electrical engagement with theresistance element at the innermost portion of the terminals.

For a better understanding of the present invention, reference may behad to the accompanying drawings wherein the same reference numeralshave been applied to like parts and wherein:

FIG. 1 is an isometric view of a preferred embodiment of a variableresistance slide control made in accord with the present invention;

FIG. 2 is a sectional view of FIG. 1 taken along lines lI-Il of FIG. 1;

FIG. 3 is a side view of the slider shown in FIGS. 1 and 2;

FIG. 4 is an exploded view of the control shown in FIG. 1, with thedielectric base and housing partially rotated to provide a better viewof the interior of the control;

FIG. 5 is a top view of the dielectric base shown in FIG. 4 with one ofthe terminals removed;

FIG. 6 is a side view of the dielectric base shown in FIG. 5; and

FIG. 7 is an end view of the dielectric base shown in FIG. 5.

Referring now to FIGS. 1 through 4 of the drawings, there is illustrateda variable resistance slide control generally indicated at 10,comprising an elongated channel shaped housing 11 formed and stampedfrom a single piece of metal and defined by a side wall 11a, a rear wall11b, and a front wall 110 having an elongated edge lld. A pair of endwalls 12 integral with the side walls have mounting tabs 13 extendingtherefrom. Depending upon the mounting requirements, the mounting tabs13 can extend rearwardly, sidewardly or forwardly from the end walls 12.The rear wall 11b and the front wall 11c are integral with the side wall11a and the end walls 12. Although the rear wall 11b is an integral partof the housing 11, the rear wall can be eliminated, except for spacedportions required to position the dielectric base, if the applicationfor the control does not require a rear closure for the control, or therear wall can be detachably secured to the housing. In accord with thepresent invention, it is essential that the metal portion of the housinghave at least an L- shaped cross section with the legs of the L definingthe front and side walls.

The open side of the housing is closed with a dielectric base 14 ofsuitable material such as laminated fibre engaging portions of the edgesof the front and the rear walls. A plurality of folded ears 19 extendingfrom the rear wall 11b and the front wall laterally over the base 14secure the base to the housing 11. The dielectric base 14 has a top edge14a abutting against the edge of the front wall, a pair of notches 14breceiving the ears 19 extending from the front wall 110, and, in apreferred form of the invention, an elongated indentation 15 spaced fromthe elongated edge 11d of the front wall 110 defines an elongated slot16 (see FIG. 1) facing a side of the housing. The bottom edge 14c of thebase has notches 14d and a pair of terminals 17 partially received inthe notches 14d are secured to the base. An elongated resistance element31 of suitable material, such as laminated fibre, having a striplikecarbonaceous or equivalent resistance film 31a deposited on a surfacethereof is secured to the inner surface 14 e of the base 14 with a pairof clinching ears 38 integral with the terminals 17. As best seen inFIG. 5, a pair of end tabs 46 of greater width than the resistanceelement 31 allow a greater clamping area for securing more rigidly theresistance element 31 to the base 14. Conductive pads 46a are depositedon the end tabs 46 in overlapping relationship with the ends of theresistance film 31a.

In a preferred form of the invention and, as seen in FIGS. 1,4 and 5,the center portions of the terminals 17 received in the notches 14d areflush with the base. The outer ends of the terminals extend through thenotches 14d (see FIG. 1) adjacent to the cut outs 47 in the rear wall11b of the housing and the inner ends of the terminal are bent up overend tabs 46 and in electrical contact with the conductive pads 46a.Integral with each of the clinching ears 38 is a bowed portion 40 (seeFIGS. 5 and 6) having a pair of edges 41a and 41b electrically connectedto the conductive pads 46a and to the ends of the resistance film 31a.The edge 41a, being the innermost portion of the terminal, engages theresistance element 31 nearer to the end of the resistance film 31a thanthe edge 41b. Clamping the terminal 17 to the base 14 causes the edges41a and 41b of the bowed portion 40 to grip the resistance element 31 inpositive electrical contact, the edge 410 being fixed close to the endof the resistance path 31a to minimize the residual resistance betweenthe resistance film and the terminal 17.

Also disposed on the inside surface Me of the base in spaced parallelrelationship to the resistance element 31 is an elongated collectorelement 30 clinched to the base by ears 37. The collector element 30 hasa top surface 33 spaced from the base and two legs 42 and 43 defining anelongated channel 32 (see FIG. 7) abut the inside surface Me of thebase. The legs 42 and 43 contain notches 35 defining a gap extendingthrough the legs and underneath the top surface 33 of the collectorelement. Extending in the gap is a resistance center tap 44 forconnecting, when desired, to a not shown center tap terminal. The gapdefined by notches 35 extending through the collector element need notbe at the center of the collector element but could be placed anywherealong the collector element 30 for connecting a tap terminal to theresistance path 31a at any point between the terminals 17. A terminal17a integral with the col members 29. As best seen in FIG. 3, the end ofeach of the spring members 29 is provided with a bearing ridge 29a. Thechannel formed by the bight portion 24 and the legs 24a and 24b receivesthe edge 1 1d of the front wall Me as well as a portion of the frontwall 110.

The uniqueness of the slider of the present invention can best beunderstood by describing general tolerances that can readily bemaintained between the front wall 11c and the legs 24a and 24b of theslider. It is well known that sheet metal can be readily obtained. withtolerances of $0.001 inch or less. Specifically, the thickness of thesheet metal from which the housing 11 was stamped and formed has athickness of 0.025 t 0.001 inch. Therefore the deviation of the frontwall of the housing from a single plane is 0.002 inch or less.Tolerances for molded parts generally are in the range of +0.003, -.O00inch, therefore, the maximum tolerance between the legs 24a and 24b ofthe U-shaped section 25 is 0.003 inch. If a dimension of +0.002 inch isadded for clearance to the dimension between the legs 24a and 24b, theminimum and maximum dimensions between the legs and the front wall are0.002 and 0.007. By providing a close bearing fit between the legs 24aand 24b of the slider and the front wall of the housing, rocking of theslider in the direction of movement of the slider is substantiallyreduced and maintained at less than 0.007 inch at the place ofengagement of the legs of the U-shaped slider with the front wall.Preferably, the bight portion 24 of the U-shaped section 25 is spacedfrom the edge 11d of the front wall 110 to eliminate any ruffness in thefeel of the slider while the slider is moved from one end of the housingto the other end. The edge 11d usually has a rough edge resulting fromblanking and shearing of the housing from a piece of sheet metal.Furthermore, the spring members 20 extending longitudinally from the leg24a urge the leg 24b against the inner surface 18 of the front wall andfurther decrease rocking motion of the slider 20.

For the purpose of constraining a contactor 21 to move with the slider,a frame 23 extends rearwardly from the leg 24b inside of the housing andthe contactor is disposed within the frame. Preferably, and in accordwiththe present invention, the frame 23 is provided with a pair ofspaced runners 28 slidably engaging the inner surface of the side wall11a. Since the bearing surfaces of the runners slidably engaging thesurface of the side wall and the bearing surfaces legs of the U-shapedsection are normal to each other, it is unnecessary to control closelythe tolerances therebetween. Any tolerances deviation in the width ofthe frame or in the thickness of the runners will not effect the rockingmotion of the slider since such deviation merely alters the spacebetween the frame 23 and the rear wall 11b and between the bight portionof the U-' shaped section and the edge 11d.

The contactor 21 comprising a pair of contacts 36a and 36b is receivedinthe frame 23d and the edges of the contactor abut the rim 23a in aninterference fit. In the assembled control, the contacts 36a resilientlyengage the resistance film 31a and contacts 36b resiliently engage thesurface 33 of the collector element 30.

Preferably and as best shown in FIG. 2 of the drawings, a tolerancecompensator 27 integral with the frame 23 limits lateral movement of theslider inside of the housing. By providing the end of the tolerancecompensator 27 behind an engageable with the pair of contacts 36aslidably engaging the resistance film 31a, the tolerance compensatorlimits lateral movement of the slider only when the slider 20 is movedlaterally in a direction away from the side wall. Lateral rocking of theslider in the opposite direction, i.e., toward the side wall, isnonexistent since the runners 28 provided on the frame of the slider arebiased by the contactor 21 and in continuous engagement with the innersurface of the side wall. Longitudinal movement of the slider is limitedby engagement of the U-shaped section of the slider with the tabs 19.The tabs 19 also prevent the contacts 36a of the contactor from engagingthe terminals 17.

While there has been illustrated and described what is at presentconsidered to be a preferred embodiment of the present invention, itwill be appreciated that numerous changes and modifications are likelyto occur to those skilled in the art, and it is intended in the appendedclaims to cover all those changes and modifications which fall withinthe true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A variable resistance slide control comprising an elongated housinghaving a front wall and a side wall extending normal to the front wall,a dielectric base mounted to the housing in spaced parallel relationshipto the side wall, the dielectric base having a top edge abutting againstthe edge of the front wall and having a bottom edge, the dielectric basebeing provided with tance element and a collector element supported onthe base, a plurality of terminals connected to the resistance elementand to the collector element for connecting the control to an externalelectrical circuit, the terminals being partially received in thenotches provided in the base, control operating means supported formovement relative to the housing, a contactor constrained to move withthe control operating means, the contactor wipably engaging saidresistance element and the collector element, the edge of the front wallof the housing and the top edge of the dielectric base being spaced fromeach other and defining an elongated slot, the control operating meanshaving a portion extending through the slot and bearing against thefront wall.

2. The control of claim 1, wherein the operating means comprises aU-shaped section interfitting with the front wall and slidably supportedthereon.

3. The control of claim 2, wherein the legs of the U- shaped section ofthe operating means slidably engage the inner and outer surfaces of thefront wall.

4. The control of claim 1, wherein the dielectric base contains anelongated indentation defining the edge thereof, and the elongatedindentation and the edge of the front wall define the elongated slotfacing a side of the housing.

5. The control of claim ll, wherein a frame extends rearwardly from oneleg of the U-shaped section of the operating means, and the contactor isconstrained to move with the frame of the operating means.

6. The control of claim 5, wherein 'a pair of runners extending from theframe of the operatingmeans slidably engage the inner surface of theside wall.

7. The control of claim 6, wherein the runners extending from the frameof the operating means prevent lateral movement of the slider toward theside wall, and a tolerance compensator integral with the frame of theoperating means and extending toward the dielectric base limits lateralmovement of the slider away from the side wall.

8. The control of claim 5, wherein a tolerance compensator extendslaterally from the frame of the operating means for limiting lateralmovement of the frame away from the side wall, the end of the tolerancecompensator being engageable with the contactor.

9. The control of claim 1, wherein the housing has a U-shaped crosssection, one of the legs of the U defining the front wall, the other legof the U defining a rear wall and the bight portion of the U definingthe side wall, the housing is of sheet metal and the slider is ofelectrically nonconductive material.

10. In a variable resistance control, the combination comprising anelongated housing having a U-shaped cross section, a dielectric basesupported by the housing and defining a first side wall of the housing,a resistance element and a collector element supported on the base, thehousing being defined by a front wall, a rear wall and a second sidewall integral with the front and rear walls, a slider comprising aU-shaped section having legs interfitting with the front wall andslidably supported thereon, the legs slidably engaging the inner andouter surfaces of the front wall, and a contactor disposed in thehousing and wipably engaging the resistance element and the collectorelement, the contactor being constrained to move with the slider.

1 l. The control of claim 10, further comprising a pair of end wallsintegral with the side wall and closing the ends of the housing.

12. The control of claim 11, wherein a pair of mounting tabs areintegral with the end walls for securing the control to a mountingpanel.

13. The control of claim 10, wherein the front wall and the dielectricbase are spaced from each other and define an elongated slot throughwhich the slider projects outwardly of the housing.

14. In a variable resistance control, the combination comprising ahousing, a dielectric base supported by the housing, a resistanceelement containing a resistance path and a collector element supportedon the base, control operating means supported for movement relative tothe housing, a contactor wipably engaging the resistance element and thecollector element and constrained to move with the operating means andterminal means joined to the resistance element for connecting the endsof the resistance path to an external electrical circuit, the terminalmeans comprising a curved portion having a first edge and a second edgespaced apart from the first edge, the first edge being disposed on theresistance element nearer said resistance path than the second edge andmaking electrical contact with the resistance path.

15. The control of claim 14, wherein the terminal means comprisesattaching means integral with the curved portion, the attaching meansaffixing the terminal means and the resistance element to said base.

16. The control of claim 15, wherein the resistance element contains anend tab and the attaching means is disposed around the end tab forsecuring the resistance element to the base.

17. A variable resistance control comprising an elongated housing havinga plurality of walls, a dielectric base supported by the housing, aresistance element containing a resistance path and a collector elementsupported on the base, a pair of end tabs integral with the resistanceelement and of greater width than the resistance element, controloperating means supported for movement relative to the housing, acontactor constrained to move with the control operator means, thecontactor wipably engaging the resistance path and the collectorelement, and a terminal joined to the base and the resistance element,the terminal having a first portion and a second portion spaced fromsaid first portion, the first portion clinching the end tabs of theresistance element to the base and the second portion making contactwith the resistance element.

18. A variable resistance control comprising an elongated housing havinga front wall and a pair of spaced side walls normal thereto, the frontwall having an exterior surface and an interior surface, the front wallof the housing and one of the side walls defining an elongated slottherebetween, a resistance element and a collector element disposed inthe housing, terminals connected to the resistance element and thecollector element for connecting the control to an external electricalcircuit, 'a contactor wipably engaging the resistance element and thecollector element, and control operating means supported for movementrelative to the housing and extending outwardly through the elongatedslot, the control operating means comprising a U-shaped sectioninterfitting with and slidably engaging the front wall, a spring bearingdisposed outside the housing and engaging the exterior surface, and aframe disposed within the housing adjacent to the interior surface, theU- shaped section connecting the spring bearing to the frame, thecontactor being constrained to move with the frame of the controloperating means.

1. A variable resistance slide control comprising an elongated housinghaving a front wall and a side wall extending normal to the front wall,a dielectric base mounted to the housing in spaced parallel relationshipto the side wall, the dielectric base having a top edge abutting againstthe edge of the front wall and having a bottom edge, the dielectric basebeing provided with notches communicating with the bottom edge, aresistance element and a collector element supported on the base, aplurality of terminals connected to the resistance element and to thecollector element for connecting the control to an external electricalcircuit, the terminals being partially received in the notches providedin the base, control operating means supported for movement relative tothe housing, a contactor constrained to move with the control operatingmeans, the contactor wipably engaging said resistance element and thecollector element, the edge of the front wall of the housing and the topedge of the dielectric base being spaced from each other and defining anelongated slot, the control operating means having a portion extendingthrough the slot and bearing against the front wall.
 1. A variableresistance slide control comprising an elongated housing having a frontwall and a side wall extending normal to the front wall, a dielectricbase mounted to the housing in spaced parallel relationship to the sidewall, the dielectric base having a top edge abutting against the edge ofthe front wall and having a bottom edge, the dielectric base beingprovided with notches communicating with the bottom edge, a resistanceelement and a collector element supported on the base, a plurality ofterminals connected to the resistance element and to the collectorelement for connecting the control to an external electrical circuit,the terminals being partially received in the notches provided in thebase, control operating means supported for movement relative to thehousing, a contactor constrained to move with the control operatingmeans, the contactor wipably engaging said resistance element and thecollector element, the edge of the front wall of the housing and the topedge of the dielectric base being spaced from each other and defining anelongated slot, the control operating means having a portion extendingthrough the slot and bearing against the front wall.
 2. The control ofclaim 1, wherein the operating means comprises a U-shaped sectioninterfitting with the front wall and slidably supported thereon.
 3. Thecontrol of claim 2, wherein the legs of the U-shaped section of theoperating means slidably engage the inner and outer surfaces of thefront wall.
 4. The control of claim 1, wherein the dielectric basecontains an elongated indentation defining the edge thereof, and theelongated indentation and the edge of the front wall define theelongated slot facing a side of the housing.
 5. The control of claim 1,wherein a frame extends rearwardly from one leg of the U-shaped sectionof the operating means, and the contactor is constrained to move withthe frame of the operating means.
 6. The control of claim 5, wherein apair of runners extending from the frame of the operating means slidablyengage the inner surface of the side wall.
 7. The control of claim 6,wherein the runners extending from the frame of the operating meansprevent lateral movement of the slider toward the side wall, and atolerance compensator integral with the frame of the operating means andextending toward the dielectric base limits lateral movement of theslider away from the side wall.
 8. The control of claim 5, wherein atolerance compensator extends laterally from the frame of the operatingmeans for limiting lateral movement of the frame away from the sidewall, the end of the tolerance compensator being engageable with thecontactor.
 9. The control of claim 1, wherein the housing has a U-shapedcross section, one of the legs of the U defining the front wall, theother leg of the U defIning a rear wall and the bight portion of the Udefining the side wall, the housing is of sheet metal and the slider isof electrically nonconductive material.
 10. In a variable resistancecontrol, the combination comprising an elongated housing having aU-shaped cross section, a dielectric base supported by the housing anddefining a first side wall of the housing, a resistance element and acollector element supported on the base, the housing being defined by afront wall, a rear wall and a second side wall integral with the frontand rear walls, a slider comprising a U-shaped section having legsinterfitting with the front wall and slidably supported thereon, thelegs slidably engaging the inner and outer surfaces of the front wall,and a contactor disposed in the housing and wipably engaging theresistance element and the collector element, the contactor beingconstrained to move with the slider.
 11. The control of claim 10,further comprising a pair of end walls integral with the side wall andclosing the ends of the housing.
 12. The control of claim 11, wherein apair of mounting tabs are integral with the end walls for securing thecontrol to a mounting panel.
 13. The control of claim 10, wherein thefront wall and the dielectric base are spaced from each other and definean elongated slot through which the slider projects outwardly of thehousing.
 14. In a variable resistance control, the combinationcomprising a housing, a dielectric base supported by the housing, aresistance element containing a resistance path and a collector elementsupported on the base, control operating means supported for movementrelative to the housing, a contactor wipably engaging the resistanceelement and the collector element and constrained to move with theoperating means and terminal means joined to the resistance element forconnecting the ends of the resistance path to an external electricalcircuit, the terminal means comprising a curved portion having a firstedge and a second edge spaced apart from the first edge, the first edgebeing disposed on the resistance element nearer said resistance paththan the second edge and making electrical contact with the resistancepath.
 15. The control of claim 14, wherein the terminal means comprisesattaching means integral with the curved portion, the attaching meansaffixing the terminal means and the resistance element to said base. 16.The control of claim 15, wherein the resistance element contains an endtab and the attaching means is disposed around the end tab for securingthe resistance element to the base.
 17. A variable resistance controlcomprising an elongated housing having a plurality of walls, adielectric base supported by the housing, a resistance elementcontaining a resistance path and a collector element supported on thebase, a pair of end tabs integral with the resistance element and ofgreater width than the resistance element, control operating meanssupported for movement relative to the housing, a contactor constrainedto move with the control operator means, the contactor wipably engagingthe resistance path and the collector element, and a terminal joined tothe base and the resistance element, the terminal having a first portionand a second portion spaced from said first portion, the first portionclinching the end tabs of the resistance element to the base and thesecond portion making contact with the resistance element.